There is still no official confirmation as to what exactly happened to O’Brien or what went wrong that caused the accident. Initial reports had him falling off the back of a moving set piece designed to look like a train and being run over by a car. Then we heard that while he fell off a moving set piece, the damage was caused by landing face first onto the pavement rather than a car. Now we have a more detailed look at what happened thanks to a WorkSafeBC report that was leaked to the press.

“An action sequence was being filmed for a motion picture,” the report reads. “This young worker was attached to a vehicle by a harness, lanyard and overhead truss system when he climbed onto the back of another vehicle. As the vehicles slowed, the trailing vehicle the worker was anchored to slowed more rapidly than the vehicle the worker climbed onto.”

So the car he started on and was harnessed to slowed down too much, pulling the actor off the car he had climbed onto. It is still unclear whether Dylan’s injuries were caused by being pulled off the car onto the road, or if the car he was harnessed to actually hit or ran over him.

“The resumption of principal photography on Maze Runner: The Death Cure has been further delayed to allow Dylan O’Brien more time to fully recover from his injuries,” 20th Century Fox said in a statement. “We wish Dylan a speedy recovery and look forward to restarting production as soon as possible.”